performSelectorInBackground具有多个参数 [英] performSelectorInBackground with multiple params

问题描述

如何使用performSelectorInBackground调用具有多个参数的方法？

How can I call a method with multiple params like below with performSelectorInBackground?

示例方法：

-(void) reloadPage:(NSInteger)pageIndex firstCase:(BOOL)firstCase;

推荐答案

问题是 performSelectorInBackground ：withObject：只需要一个对象参数。解决此限制的一种方法是将参数的字典（或数组）传递给解包参数并调用实际方法的包装器方法：

The problem is that performSelectorInBackground:withObject: takes only one object argument. One way to get around this limitation is to pass a dictionary (or array) of arguments to a "wrapper" method that deconstructs the arguments and calls your actual method:

- (void)callingMethod {
    NSDictionary * args = [NSDictionary dictionaryWithObjectsAndKeys:
                            [NSNumber numberWithInteger:pageIndex], @"pageIndex",
                            [NSNumber numberWithBool:firstCase], @"firstCase",
                            nil];
    [self performSelectorInBackground:@selector(reloadPageWrapper:)
                           withObject:args];
}

- (void)reloadPageWrapper:(NSDictionary *)args {
    [self reloadPage:[[args objectForKey:@"pageIndex"] integerValue]
           firstCase:[[args objectForKey:@"firstCase"] boolValue]];
}

- (void)reloadPage:(NSInteger)pageIndex firstCase:(BOOL)firstCase {
    // Your code here...
}

这种方式你只是传递一个单一参数到后台调用，但该方法可以构造您需要的多个参数真正的调用（这将发生在同一个后台线程）。

This way you're only passing a "single" argument to the backgrounding call, but that method can construct the multiple arguments you need for the real call (which will take place on the same backgrounded thread).

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